Mounting for vibrator of electrical musical instrument



J. T. KUNZ Feb.l1,195 8 MOUNTING FOR ViIBRATOR OF ELECTRICAL MUSICAL INSTRUMENT Filed June 1, 1951 2 Sheets-Sheet 1 INVENTOR. $9605 7 Kan/z WWW ATTORNEYS.

J. T. KUNZ Feb. 11, 1958 MOUNTING FOR VIBRATOR OF ELECTRICAL MUSICAL INSTRUMENT 2 Sheets-Sheet 2 Filed June 1, 1951 /Re/a/ive Bell Amplifude JNVENTOR. Jeeps 7. .///\/z BY ZZZ/(Mm ATTORNEYS United States fiatent O a MOUNTING FOR VIBRATGR OF ELECTRICAL MUSICAL INSTRUMENT Jacob T. Kunz, North Hills, Pa., assignor to Schulmerich Electronics, Incorporated, Sellersville, Pin, a corporation of Pennsylvania Application June 1, 1951, Serial No. 229,380 3 Claims. c1. 84-403) This invention relates to musical instrument and especially to an improved damping and cut-off means for the vibrator of electric musical instruments producing true bell or chime tone.

Various types of vibrators have been used in bell or chime tone electric music instruments, the vibrating elements of such instruments having been made in the form of rods, both solid and hollow, as well as other shapes. In such an electric musical instrument, the vibrations of the vibrator usually are translated into electrical vibrations which are amplified, modified, and then changed into sound by a loud speaker so as to produce the bell tones.

Vibrators have been arranged with one end thereof fixed and the other free to vibrate, or they have been supported so that both ends are unrestrained and free to move. In the production of bell tones, it is particularly necessary to arrange the parts of the instrument so as to obtain from a vibrator the desired characteristic tone, the correct relationship of partials, and the proper relationship of partials, and the proper relationship of damping of the partials relative to each other after vibration starts.

One of the objects of the present invention is to provide an improved vibrator or tone generator for an electric musical instrument to produce a bell tone, or other desired tone, having the correct damping relationship of the partials to each other during the time the vibrator is vibrating and as it comes to rest.

Another of the objects of the invention is to provide an improved damping arrangement which is intermittently efiective during the first portion of the vibration of a vibrator and which thereafter becomes increasingly effective of accelerates the damping.

In one aspect of the invention, the damping means is mounted on a rod or vibrator so that it will be activated when the rod is set into vibration so as to intermittently damp the vibration. The damping means normally rests on a fixed surface or body and thus the effective mass is high. When the vibrator is set into vibration, the damp ing means will be displaced from the fixed surface so that the effective damping mass becomes low. As the vibration amplitude diminishes with time after the start thereof, the damping means will come into contact with and will finally come to rest on said fixed surface so as to accelerate the damping. Preferably, the surface is arranged so as to provide frictional contact between it and the damping means.

The energy in a rod, particularly at the end thereof, will be made up of the total energy of all of the partials in the rod, this being especially true in a vibrator having a free end. In the present invention, the damping device is effective intermittently during the first part of the vibration or when the amplitude of the vibrator is the greatest. As the vibration decays, the damping device will damp the same more rapidly.

In a preferred form of the invention, the vibrator can have an aperture adjacent the end thereof through which a flexible vibration absorbing member of solid material is loosely held. One part of the flexible element or 2,322,715 Patented Feb. 11, 1958 ice thread normally rests on a fixed surface so that when the vibrator is at rest, there is a connection therebetween.

Upon setting the vibrator into vibration, the flexible element will be in contact intermittently with the vibrator so as to damp it at intervals, the flexible element jumping out of contact with the fixed surface or body. As the vibration amplitude of the vibrator is reduced, the damping means will tend to come to rest upon the fixed surface 'more often and thus when it is in contact with both the vibrator and fixed surface, it will serve to more rapidly damp the vibrations. Also, there may be frictionally retarded movement of the flexible element by the fixed surface. Finally, the damping means will remain on the fixed surface and quickly cut off the vibrations or reduce them to imperceptible or ineffective values. The damping means can be mounted on a hori-- zontal rod or vibrator or can be on a vertical element- The flexible element may take various forms and may be a stiff wire mounted on the vibrator in such a way that it can jump clear thereof intermittently.

This invention is 'an improvement on applicants copending application Serial No. 60,469 filed November 17, 1948, now Patent No. 2,622,467 issued December 23, 1952.

The vibrator and damping arrangement of the present invention can be used for various purposes, one of such being, for example, in conjunction with the vibrator in the musical instrument described in copending application Serial No. 247,585 filed September 21, 1951, now Patent No. 2,770,994 granted November 20, 1956.

In musical instruments of the type mentioned therein, the electrical pick-ups or collectors can be arranged adjacent to the rods and connected through amplifiers to a suitable loud speaker combination. The amplifiers and loud speakers can be selected to modify or eliminate the partials as desired so as to produce a true bell tone.

In a rod having free ends, each of the partials will have an anti-node at the free end thereof so that energy will be absorbed from all of the partials intermittently at the beginning of the vibration. Where a vibrator is fixed at both ends, it is necessary to place the damping device quite close to a fixed end so as to only disproportionately affect a few of the partials. The damping device should be located where there are no nodes of the significant partials used in producing the desired tone.

These and other objects, features, and advantages of the invention will become apparent from the following description and drawings.

In the drawings:

Fig. 1 is a top plan view of a portion of an instrument having one form of the invention.

Fig. 2 is a side view partly in section of a portion of the instrument shown in Fig. 1.

Fig. 3 is an enlarged fragmentary perspective view of one form of the invention.

Fig. 4 is a graph comparing various damping means.

Fig. 5 is a schematic block diagram of one manner in which the apparatus may be used.

Fig. 6 is a fragmentary sectional view of another form of the invention.

An assembly of fixed-free rods 10 in an electric bell instrument, such as described in copending application Serial No. 247,585, filed September 21, 1951, now Patent No. 2,770,994, granted November 20, 1956, is shown in Fig. 1, said rods being mounted on a fixed block 11. The rods 19 preferably are arranged to be acoustically integral with the block and suitable selectively operable strikers (not shown) are appropriately located for the purpose of selectively setting the rods into vibration.

The fixed block 11 is carried by resilient supporting brackets 12 from the main frame means 13. Adjacent the free ends of each of said rods 10, apertures can be pro vided therethrough receiving a damping means 15. The damping means 35 in the form shown is a flexible element. Knots 1e and 17 can be placed in the thread on either side of the rod so as to limit the position of the flexible element 15, relative thereto; When theflexible damping means 15 is at rest, knot 16 will Support the thread on the rod. Knot 17 I will limit'the upward movement of the damping means. The thread may be of any suitable material, for example, nylon.

Located below the rods 10 is a fixed body or bar 18, said body or bar preferably having a series of corrugations or grooves 19. The bar 18 can be fastened near its ends 29 to frame members 13. The corrugations or grooves 19 may be continuous along the effective length of the bar, these being, for example, in the form of a screw thread. The bar is arranged in relation to the flexible elements 15 in the rods in such a manner that the flexible elements will rest thereon.

When a rod 10 is struck, or put into vibration, the damping element 15 will vibrate relative to the rod. Also, it will jump olf of the grooved bar 18. Thus, the flexible element 15 will only intermittently come into contact I with the rod 159 and so the damping effect thereof will be intermittent. As a result, it will intermittently serve to damp all of the vibrations and will not substantially afiect the partial structure of the electrical vibration picked up in the amplifier circuit. This is in contrast to a fixed weight permanently fastened to some point along the rod because such a weight will only affect one or some of the partials.

As the amplitude of vibration decreases, the flexible damping element 15 of solid material will come into and remain in contact with bar 18, there being a frictional contact therewith as the flexible damping element 15 vibrates relative thereto. When flexible element 15 is in contact with the fixed surface or bar 18, the damping effect will be accelerated; thus there will be an increase 7 matically the general relations between relative hell am- I plitu-de and time after the rod has been struck. Curve A illustrates the relations existing in an undamped fixedfree rod. The amplitude increases rapidly at first and then gradually dies out, the vibration persisting for a long time. 7

When intermittent damping only is used, without the benefit of the damping accelerating feature of this invention, curve B shows the relations existent. It is to be noted that the amplitude dies out relatively rapidly after the maximum amplitude has been reached and then dies out gradually. Curve C shows the effect when there is intermittent damping and cut-off or damping accelerating as in the present invention. It is seen that the amplitude approaches zero in much less time than that involved in curve B. The intermittent types of damping illustrated in curve B operate effectively for some purposes, but it has been found that a better result is obtained for many purposes when the intermittent and cut-olf arrangement of the present invention is employed.

As seen in Figure 5, bell mechanism made in accordance with the present invention can be connected to suitable amplifiers, the amplifiers in turn being connected to loud-speakers. The strikers can be selectively operable to produce the desired bell tones and music. The rods are tuned and the amplifier circuits arranged so as to obtain the desired be l tone in the loud-speaker. Also, the loudspeaker can be properly chosen to assist in obtaining the desired partial relationship.

In addition to the flexible type damping elements 15, other types of intermittent and cut-ofi damping means can be employed, as an example, a wire can be loosely mounted relative to the rod and positioned so that its other end is normally resting on bar 18 or a similar fixed surface. Such an arrangement is illustrated in Fig. 6 wherein rod 22 has an aperture 23 loosely receiving the end of wire 24. Wire 24 can be loose frictional contact with the fixed bar 25. The end of wire 24 also could be loosely pivotally mounted (not shown) in apertures in the vibrator rod.

When the vibrator rod is struck, the wire 24 will move relative to the rod and also will jump-off the fixed surface until the amplitude of the rod decreases as for the previously described flexible element. A spring (not shown) or other similar forms also can be loosely hung or mounted on the rod so as to operate in the same manner as the flexible element. The wire can be of a suitable metal or other material as desired.

It is to be understood that various changes can be made in the details of construction of the invention and that the invention can be applied to various types of vibrators and musical instruments without departing from the spirit of the invention except as defined in the annexed claims.

What is claimed is:

1. An electric music instrument damping arrangement including a vibrator element, an intermittently acting solid material flexible damping means operatively loosely mounted and resting on said vibrator element, means loosely holding said damping means on said vibrator element, said damping means normally being in contact with said vibrator element when the vibrator element is at rest, said damping means being movable relative to said vibrator means upon vibration of said vibrator element, and a body having a grooved surface spaced from said vibrator element, a portion of said flexible damping means normally resting in one of the grooves of said grooved surface when the vibrator means is at rest but intermittently contacting the surface during at least part of the vibration and continuously contacting the surface as vibration decays.

2. An electric music instrument tone generator including a vibrator having an aperture therein, a flexible thread loosely mounted in said aperture on said vibrator, said thread being rendered movable relative to said vibrator by vibration thereof and intermittently out of damping relationship therewith, and a relatively fixed body spaced from said vibrator and located adjacent said thread so that said thread rests thereon when the vibrator is at 'rest but moves intermittently out of contact with said body upon initiation of vibration of said vibrator, said thread again resting on said body as vibration decays so as to accelerate damping of said vibrator as the vibration decays.

3. An electric music instrument tone generator including a vibrator, a wire loosely pivotally mounted on said vibrator, said wire being rendered pivotally and loosely movable relative to said vibrator by vibration thereof and intermittently out of damping relationship therewith, means loosely holding said wire on said vibrator so that said wire is in contact therewith when the vibrator is at rest, and a relatively fixed'body located adjacent said vibrator and wire, so that said wire rests thereon when the vibrator is at rest but iumps therefrom during the first part of the vibration of said vibrator, said wire hing intermittently in contact with said'body during the first part of the vibration and again comes to rest thereon so as to -accelerate damping of the vibration.

' i Referenees ECited the file of this patent a UNITED STATES PATENTS 725,842 Hennl Apr. 21, 1903 890,341 'Deagan June 9, 1908 Sundt Sept. 30, 1941 Miessner Dec. 24, 1946 *Rowe Oct. 11, 1949 Rowe Mar. 4, 1952 Kunz Dec. 23, 1952 

